io-char : S/W Buffer Overrun Error

I’ve a lonTALK adapter connected to the serial port. This adapter has a CPU on it. Now, I’ve built a driver for handling this adapter. This driver sits on top of the serial driver devc-ser8250. (i.e. uses devc-ser8250 to fetch/send the data). Now, this adapter driver seems to work fine with a normal serial port but when I tested it on the actual TTL port the adapter was connected to, I’m not able to receive any notification from the serial driver (devc-ser8250), which is facilitated by ionotify().

The contents of the sloginfo says that io-char: S/W Buffer Overrun Error…
Moresoever, when I do a simple ‘cat /dev/ser1’ on this port, the cursor keeps on blinking which i assume is the data is coming really fast.

suggestions on how to tackle this.